Suppress MSVC warning '<': expression always false (#982)

Adds a spot suppression for MSVC warning C4296: '<' : expression is
always false. MSVC's "always constant" warnings tend to trigger on
tempalted code based on the specific instantiation's values,
disregarding that the template itself it not always constant.

Fixes #981

CHANGELOG.md

@@ -26,6 +26,9 @@ different versioning scheme, following the Haskell community's
 * Fixed ambiguous call to `maybe::operator==` that breaks GCC 9
   build. ([Pull request
   #975](https://github.com/microsoft/bond/pull/975))
+* Fixed MSVC warning C4296: "'<': expression is always false" in protocol.h.
+  ([Issue
+  #981](https://github.com/microsoft/bond/issues/981))
 
 ## 8.1.0: 2019-03-27 ##
 

cpp/inc/bond/core/protocol.h

@@ -194,11 +194,20 @@ namespace detail
 {
 #if !defined(_MSC_VER) || _MSC_VER >= 1900
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4296) // C4296: '<' : expression is always false
+#endif // _MSC_VER
+
     // Avoid std::max due to a bug in Visual C++ 2017.
     template <std::size_t V0, std::size_t V1>
     struct max_of
         : std::integral_constant<std::size_t, (V0 < V1 ? V1 : V0)> {};
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif // _MSC_VER
+
     template <typename List> struct
     max_size;